The Apostle Paul
Romans 8:4BSB·traditional attribution

so that the righteous standard of the law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit.

John Calvin Reformed @genevareformer

4. That the justification of the law might be fulfilled, etc. They who understand that the renewed, by the Spirit of Christ, fulfil the law, introduce a gloss wholly alien to the meaning of Paul; for the faithful, while they sojourn in this world, never make such a proficiency, as that the justification of the law becomes in them full or complete.

Matthew Henry Presbyterian @wholebiblehenry

I. The apostle here beings with one signal privilege of true Christians, and describes the character of those to whom it belongs: There is therefore now no condemnation to those that are in Christ Jesus, Rom 8:1. This is his triumph after that melancholy complaint and conflict in the foregoing chapter - sin remaining, disturbing, vexing, but, blessed be God, not ruining.

Commenting on Romans 8:1-9

John Gill Reformed Baptist @doctorgill

That the righteousness of the law might be fulfilled in us,.... By the righteousness of the law, is not meant the righteousness of the ceremonial law, though that was fulfilled by Christ; but of the moral law, which requires holiness of nature, righteousness of life, and death in case of disobedience; active righteousness, or obedience to the precepts of the law, is designed here.